Abstract: A laser positioning system includes a laser scanner, a first positioning tag, a second positioning tag, and a processing unit. The laser scanner is disposed on a mobile carrier and is for emitting a light beam to a positioning board and receiving a plurality of reflected light spot signals generated by the light beam reflected from the positioning board. The first positioning tag and the second positioning tag are for reflecting the light beam to generate a first positioning signal and a second positioning signal to the laser scanner. The processing unit is for finding information of positions of the light beam projected on the first positioning tag and the second positioning tag, and filtering the reflected light spot signals to define a reference coordinate for the processing to calculate relative positions of the laser scanner and the positioning board according to the reference coordinate.

Abstract: A method for identifying an obstacle (O) in the laser beam (F) of a lidar system includes: commanding the transmission of a laser beam (F); and receiving a lidar signal (S) corresponding to the reflection of the beam (F) on a diffuser present in the beam (F). The detection method further includes: evaluating a set of first parameters of the lidar signal, the set of first parameters including at least an amplitude and a duration, a first detection moment being defined for the lidar signal (S), the duration being defined at each moment as the time elapsed since the first detection moment; identifying an obstacle (O) present in the beam (F) when the amplitude is greater than a first threshold and the duration is greater than a second threshold; and decreasing the power of the beam (F).

Abstract: Some embodiments of the invention include a coordinate measuring machine for detecting the position and alignment of a spatially movable measuring aid. The coordinate measuring machine may include a retroreflector; a base; a support, which is fixed on the base rotatably about a first rotation axis; a beam directing unit, which is fixed to the support rotatably about a second rotation axis substantially orthogonal to the first rotation axis; means for detecting a rotation angle of the support relative to the base; and means for detecting a rotation angle of the beam directing unit relative to the support. In some embodiments, the beam directing unit comprises a laser emission and reception optical unit and a first optical distance measuring unit having at least one first distance measuring device for measuring the distance to a retroreflector of the measuring aid by means of a first measurement radiation.

Abstract: Embodiments use holographic projection in augmented reality to visualize a building in 3D and show, as a holographic figure, the position of personnel in the building. In some embodiments, a user can “tap” on a holographic figure to view data on that person, such as skin temperature, room temperature, heart rate, etc.

Abstract: A distance measurement device controls an emission direction of a laser beam in a light projection device and a reception direction of a laser beam in a light reception device, obtains a reception intensity of the laser beam received by the light reception device, determines whether or not the laser beam received by the light reception device is a laser beam reflected by a target of distance measurement on the basis of a reception direction of the laser beam, a period of time between when the light projection device emits the laser beam and when the light reception device receives the laser beam, a reception intensity of the laser beam, and determination information, and calculates a distance to the target in a case when the laser beam received by the light reception device is the laser beam reflected by the target.

Abstract: A method of imaging a scene includes generating a temporally varying optical intensity pattern from at least one continuous wave (CW) light beam. The method also includes illuminating at least one portion of the scene with the temporally varying optical intensity pattern so as to cause a photon to scatter or reflect off the at least one portion of the scene. The photon reflected or scatted from the at least one portion of the scene is detected using a single-photon detector. Based on the temporally varying optical intensity pattern and a time of flight of the photon detected, a distance between the single-photon detector and the at least one portion of the scene is estimated.

Abstract: Provided are methods and systems for aligning multiple parts using simultaneous scanning of features of different parts and using feature-based coordinate systems for determining relative positions of these. Specifically, a feature-based coordinate system may be constructed using one or more critical dimensions between features of different parts. The scanner may be specifically positioned to capture each of these critical dimensions precisely. The feature-based coordinate system is used to compare the critical dimensions to specified ranges. The position of at least one part may be adjusted based on results of this comparison using, for example, a robotic manipulator. The process may be repeated until all critical dimensions are within their specified ranges. In some embodiments, multiple sets of features from different parts are used such that each set uses its own feature-based coordinate system. The part adjustment may be performed based on the collective output from these multiple sets.

Abstract: Embodiments describe a solid state electronic scanning LIDAR system that includes a scanning focal plane transmitting element and a scanning focal plane receiving element whose operations are synchronized so that the firing sequence of an emitter array in the transmitting element corresponds to a capturing sequence of a photosensor array in the receiving element. During operation, the emitter array can sequentially fire one or more light emitters into a scene and the reflected light can be received by a corresponding set of one or more photosensors through an aperture layer positioned in front of the photosensors. Each light emitter can correspond with an aperture in the aperture layer, and each aperture can correspond to a photosensor in the receiving element such that each light emitter corresponds with a specific photosensor in the receiving element.

Abstract: In general, certain embodiments of the present disclosure provide a detection and avoidance system for a vehicle. According to various embodiments, the detection and avoidance system comprises an imaging unit configured to obtain a first image of a field of view at a first camera channel. The first camera channel filters radiation at a wavelength, where one or more objects in the field of view do not emit radiation at the wavelength. The detection and avoidance system further comprises a processing unit configured to receive the first image from the imaging unit and to detect one or more objects therein, as well as a notifying unit configured to communicate collision hazard information determined based upon the detected one or more objects to a pilot control system of the vehicle. Accordingly, the pilot control maneuvers the vehicle to avoid the detected objects.

Abstract: The invention relates to a device (1) and a method for determining the action of active ingredients on nematodes and other organisms in aqueous tests.

Abstract: An optical module includes a carrier, a light source disposed on an upper side of the carrier, an optical sensor disposed on the upper side of the carrier, and a housing disposed on the upper side of the carrier over the light source and the optical sensor. The housing defines a first aperture exposing at least a portion of the light source and a second aperture exposing at least a portion of the optical sensor. An outer sidewall of the housing includes at least one singulation portion adjacent to the upper side of the carrier and perpendicular to the upper side of the carrier.

Abstract: Provided is a position locating instrument for a position locating method in which position locating instruments that transmit and receive light beams are arranged in series connection. The position locating instruments reduce error factors and improve measurement accuracy by providing all or some of necessary position and attitude parameters. The position locating instrument has at least one light emission port through which light from a wavelength-changeable light source is emitted; and at least one light receiving port that receives light emitted or reflected by an adjacent position locating instrument. The light emitted from the light emission port has a fanlike pattern and has an emission angle varying, as a monotonic function of a wavelength of the light, in a direction perpendicular to a direction in which the light spreads in the fanlike pattern.

Abstract: Embodiments describe a solid state electronic scanning LIDAR system that includes a scanning focal plane transmitting element and a scanning focal plane receiving element whose operations are synchronized so that the firing sequence of an emitter array in the transmitting element corresponds to a capturing sequence of a photosensor array in the receiving element. During operation, the emitter array can sequentially fire one or more light emitters into a scene and the reflected light can be received by a corresponding set of one or more photosensors through an aperture layer positioned in front of the photosensors. Each light emitter can correspond with an aperture in the aperture layer, and each aperture can correspond to a photosensor in the receiving element such that each light emitter corresponds with a specific photosensor in the receiving element.

Abstract: A Lidar system is provided. The Lidar system comprises: a set of light sources configured to emit a plurality of light beams; a set of optical fiber elements, wherein each of the set of light sources is optically coupled to a first end of one or more optical fiber elements from the set of optical fiber elements; and at least one mounting unit comprising a structure configured to receive a second end of the set of optical fiber elements at one or more directions thereby affecting a direction of the plurality of light beams individually.

Abstract: An optoelectronic module operable to collect distance data via a time-of-flight mode and a time-of-flight-triangulation mode includes an illumination assembly and an imaging assembly. The imaging assembly includes at least one demodulation pixel operable to determine distance to an object via a time-of-flight mode and a time-of-flight-triangulation mode. Multi-path distance inaccuracies can be mitigated in some implementations.

Abstract: The present disclosure provides a high resolution structured light system that is also capable of maintaining high throughput. The high resolution structured light system includes one or more image capture devices, such as a camera and/or an image sensor, a projector, and a blurring element. The projector is configured to project a binary pattern so that the projector can operate at high throughput. The binary projection pattern is subsequently filtered by the blurring element to remove high frequency components of the binary projection pattern. This filtering smoothes out sharp edges of the binary projection pattern, thereby creating a blurred projection pattern that changes gradually from the low value to the high value. This gradual change can be used by the structured light system to resolve spatial changes in the 3D profile that could not otherwise be resolved using a binary pattern.

Abstract: A Lidar system is provided. The Lidar system may comprise: a plurality of light sources configured to emit a plurality of light beams, the plurality of light sources are mounted to a first mounting apparatus comprising a cooling feature; a plurality of optical fiber elements, and each of the plurality of light sources is optically coupled to an input end of one or more optical fiber elements from the plurality of optical fiber elements; and a second mounting apparatus comprising at least one mounting unit coupled to an emitting end of the plurality of optical fiber elements, and the at least one mounting unit is configured to control an output direction of the plurality of light beams individually, and a distribution pattern of the plurality of light beams emitted from the emitting end of the plurality of optical fiber elements.

Abstract: A sensing method, including: emitting a signal beam; sampling the reflected signal at a sensor with a field of view larger than the signal beam; and determining a surface parameter based on the bright and dark regions associated with the sampled signal.

Abstract: The invention relates to a depth sensor module and depth sensing method. The depth sensor module and method is adapted to include a light detector part and emitting part with a least two light sources spatially offset in the direction of the triangulation baseline. In some of the embodiments, the pixel field of the image sensor in the light detector part consists of time-of-flight pixels. Depth measurements derived by triangulation can be used to calibrate depth maps generated by the time-of-flight measurements.

Abstract: Laser radar systems include focusing optical systems having a retroreflector such as a corner cube that is translatable with respect to an objective lens. The retroreflector provides a selected retardance to an interrogation optical beam that is directed to a target as well as to a returned portion of the interrogation optical beam that is directed to a detection system. Typically, an input linearly polarized interrogation beam is returned by the retroreflector as a circularly polarized beam that is directed to the target. Returned beam portions from the target are coupled by the retroreflector to a detection system in a linear polarization that is orthogonal to that of the input linearly polarized optical beam. The retroreflector produces state of polarization changes based on retardance associated with total internal reflection from coated or uncoated optical surfaces. Retroreflector surfaces that are not to introduce retardance are coated with suitable zero or low retardance coatings.

Abstract: A method of taking pictures for generating three-dimensional image data is disclosed. The method includes continuously illuminating a target object with an environmental light; using an image sensor to receive the light reflected from the target object to generate a first electrical image signal; illuminating the target object with an active light generated from an active light source unit during the period of exposure by the environmental light; using the same image sensor to receive another reflected light to generate a second electrical image signal; using an image processing unit to receive the first and second electrical image signals, convert the first electrical image signal to a two-dimensional image data, and subtract the first electrical image signal from the second electrical image signal to generate three-dimensional depth data; and combining the two-dimensional image data and the three-dimensional depth data to generate the three-dimensional image data.

Abstract: A measuring device for triangulation measurement comprises a light transmitter for emitting illuminating light; a transmitting optical system for directing the illuminating light in a light pattern in the direction of an object; a light receiver for recording an image; a control and evaluation unit, which determines, in a measurement mode, form or position information of the object based on a measurement image of the light receiver. According to the invention the control and evaluation unit can change over between the measurement mode and a data reading mode, wherein the control and evaluation unit, in the data reading mode, evaluates the image with respect to encoded parameter data, and, in a subsequent measurement mode, uses the parameter data read in this way. In addition, a corresponding method for triangulation measurement is described.

Abstract: A laser detection and ranging device for detecting an object under a water surface, the laser detection and ranging device having a laser transmitter being configured to modulate a laser beam by a binary pseudo-random coding sequence to obtain a modulated laser beam, and to transmit the modulated laser beam towards the water surface, a laser detector for detecting a reflected laser beam, the reflected laser beam forming a reflected version of the transmitted laser beam, and a processor for detecting the object under the water surface upon the basis of the reflected laser beam.

Abstract: A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel that defines a front surface and a rear surface, light emitters optically connected to the panel so as to generate light that propagates by total internal reflection inside the panel, and light detectors optically connected to the panel so as to define a grid of propagation paths inside the panel between pairs of light emitters and light detectors. Each of said light emitters is a VCSEL array, each said VCSEL array including a plurality of VCSELs driven in parallel to collectively form one light emitter. Preferably, each light detector is optically connected to the panel via an angular filter, tailored to pass light to the detector in an angular range in which the emitters operate.

Abstract: A binocular with an integrated rangefinder consisting of two tubes with observation channels, the optical systems of which include a Schmidt-Pechan prism reversion system with at least half-pentagonal prism and a Schmidt roof prism is provided. The laser transmitter of the transmitted infrared beam path is arranged in the first tube in parallel with the first observation channel towards the observed object and, furthermore, the display with an illuminated reticle and light beam is accommodated in the first tube, which, after passing through the integration display prism and the second separation layer on the reflective wall of the half-pentagonal prism and through the reversion system, is integrated into the first observation channel of the first tube.

Abstract: A method of balancing colors of three-dimensional (3D) points measured by a scanner from a first location and a second location. The scanner measures 3D coordinates and colors of first object points from a first location and second object points from a second location. The scene is divided into local neighborhoods, each containing at least a first object point and a second object point. An adapted second color is determined for each second object point based at least in part on the colors of first object points in the local neighborhood.

Abstract: A multispectral lidar system includes a laser configured to emit a pulse of light including a first wavelength, scanner configured to direct the emitted pulse of light in accordance with a scan pattern, a receiver including a first detector and a second detector, and a controller. The first detector is configured to detect the emitted pulse of light scattered by a remote target, and the second detector is configured to detect light scattered or emitted by the remote target and including a second wavelength. The scanner provides, at any point in time, a fixed spatial relationship between the fields of view over which the light with the first wavelength and the second wavelength is received. A controller can determine a distance to the remote target and use this distance to modify a measurement of the property of the remote target based on the light detected by the second detector.

Abstract: A physical quantity distribution calculation program for visualizing a physical quantity distribution in a target space is disclosed. The program causes the computer to perform processes of: based on positional information on a plurality of grid points and physical quantities obtained respectively at the plurality of grid points by the numerical analysis, grouping the grid points into groups of neighboring grid points having the same physical quantity; and determining the physical quantity to be visualized by each of a plurality of pixels which are fewer than the grid points, the determining process includes; extracting at least one group including at least one of grid points corresponding to the pixel, identifying the group including the largest number of grid points among the extracted groups, and determining that the physical quantity at the grid points belonging to the identified group is the physical quantity to be visualized by the pixel.

Abstract: A location estimation system for use with an autonomous lawn mowing robot, comprises a plurality of synthetic surfaces positioned with respect to a mowable space in an environment, a radiation source coupled to the lawn mowing robot, a detector coupled to the lawn mowing robot and configured to detect radiation reflected by objects in the environment, and a controller configured to controllably direct radiation from the radiation source to scan the environment, and to vary at least one of an output power of the directed radiation and a scan rate of the directed radiation, as a function of detected radiation reflected from one or more of the synthetic surfaces.

Abstract: A number of roadway sensing systems are described herein. An example of such is an apparatus to detect and/or track objects at a roadway with a plurality of sensors. The plurality of sensors can include a first sensor that is a radar sensor having a first field of view that is positionable at the roadway and a second sensor that is a machine vision sensor having a second field of view that is positionable at the roadway, where the first and second fields of view at least partially overlap in a common field of view over a portion of the roadway. The example system includes a controller configured to combine sensor data streams for at least a portion of the common field of view from the first and second sensors to detect and/or track the objects.

Abstract: A method for measuring a distance includes modulating the light beam at a first frequency, receiving a second beam by the optical detector to produce a first electrical signal having the first frequency and a first phase; modulating the light beam at a second frequency different than the first frequency; receiving the second beam by the optical detector to produce a second electrical signal having the second frequency and a second. After these steps, the retroreflector is moved while modulating the light beam continuously at the second frequency; and a first distance to the retroreflector is determined based at least in part on a the first and second frequencies and phases.

Abstract: A chromatic point sensor (CPS) system is provided, which compensates for potential errors due to input spectral profile intensity inconsistencies that arise when driving a CPS illumination source using different power levels. The CPS system includes an optical pen comprising a confocal optical path including a chromatically dispersive element and configured to focus different wavelengths at different distances proximate to a workpiece surface to be measured, an illumination source, and CPS electronics.

Abstract: A distance measuring apparatus includes: a light-emitting element that emits first to third pulsed beams; sensors that detect reflected light that is each of the pulsed beams reflected off an object, convert the reflected light into electrical signals, and accumulate the electrical signals over a predetermined exposure time; and a computing unit that derives a distance to the object using first to third signal amounts output by the sensors as a result of detecting, over the predetermined exposure time from first to third points in time, and the computing unit derives the distance to the object based on a first derived amount that is an amount derived using the first and second signal amounts and a second derived amount that is an amount derived using the second and third signal amounts.

Abstract: A distance between a radiation source standard point indicating a position of a radiation source and a photographic subject on a standard line passing through the radiation source standard point and a detector standard point indicating a position of a detector is measured, a distance between a first reference point positioned in a first direction which is directed towards the detector standard point from the radiation source standard point with respect to the detector standard point and the detector standard point is measured, a distance between a second reference point positioned in a direction opposite to the first direction with respect to the radiation source and the radiation source standard point is measured, and a subject thickness of the photographic subject is calculated by using the distances and a distance from the distance from the first reference point to the second reference point.

Abstract: A time-of-flight camera images an object around a corner or through a diffuser. In the case of imaging around a corner, light from a hidden target object reflects off a diffuse surface and travels to the camera. Points on the diffuse surface function as a virtual sensors. In the case of imaging through a diffuser, light from the target object is transmitted through a diffusive media and travels to the camera. Points on a surface of the diffuse media that is visible to the camera function as virtual sensors. In both cases, a computer represents phase and intensity measurements taken by the camera as a system of linear equations and solves a linear inverse problem to (i) recover an image of the target object; or (ii) to compute a 3D position for each point in a set of points on an exterior surface of the target object.

Abstract: An electronic apparatus includes a light source that outputs a laser light; a scanning unit that scans the laser light; a reflective member having a reflective surface that reflects the laser light; a light-receiving unit that receives a first reflected light reflected by the reflective member; and a signal processing unit that calculates a distance from the light source to the reflective surface using the first reflected light and determines a direction in which the laser light is output using the distance.

Abstract: A dimensioning system that analyzes a distance map for null-data pixels to provide feedback is disclosed. Null-data pixels correspond to missing range data and having too many in a distance map may lead to dimensioning errors. Providing feedback based on the number of null-data pixels helps a user understand and adapt to different dimensioning conditions, promotes accuracy, and facilitates handheld applications.

Abstract: A dimensioning system that analyzes a distance map for null-data pixels to provide feedback is disclosed. Null-data pixels correspond to missing range data and having too many in a distance map may lead to dimensioning errors. Providing feedback based on the number of null-data pixels helps a user understand and adapt to different dimensioning conditions, promotes accuracy, and facilitates handheld applications.

Abstract: An apparatus for measuring a distance can include a camera module and a film having a reference pattern. The camera module can include an infrared LED transmission unit to transmit an infrared LED light toward the film and a module unit calculating a distance from an object by using a size of a pattern projected onto the object which is obtained from an image of a camera unit. The film can include an infrared film and a plurality of holes formed in the infrared film.

Abstract: Method and apparatus for measuring a Doppler effect of a scattered light include: projecting an ultra violet (UV) light towards a target by a light emitter; receiving the UV light scatter from the target from the emitted UV light reflected from the target by a light receiver; measuring the frequency shift of the UV light scatter with respect to the emitted UV light to obtain distribution of line of sight velocity of macroscopic matters of the target corresponds to a Doppler shift; processing the distribution of the line of sight velocity to determine the Doppler effect of the UV light scatter; and separating the wind line of sight velocity as the centroid shift of the microscopic Doppler shift probability distribution.

Abstract: A handheld dimensioning system that analyzes a depth map for null-data pixels to provide feedback is disclosed. Null-data pixels correspond to missing range data and having too many in a depth map may lead to dimensioning errors. Providing feedback based on the number of null-data pixels helps a user understand and adapt to different dimensioning conditions, promotes accuracy, and facilitates handheld applications.

Abstract: Refraction angles in a planet's atmosphere are mapped using a database of known star locations and a field imager onboard a platform above the planet. The field imager is positioned to observe a region that includes a portion of the planet's atmospheric limb. A star field image is captured for the region. The star field image includes stars within the field imager's field-of-view. Using the field imager and the database, a modeled star field image is generated that is matched in size to the field-of-view associated with the star field image. The modeled star field image defines absolute locations of stars corresponding to stars appearing in the field imager's field-of-view. Differences between the absolute locations and locations of the images of stars are indicative of a limb refraction angle field.

Abstract: A handheld dimensioning system that analyzes a depth map for null-data pixels to provide feedback is disclosed. Null-data pixels correspond to missing range data and having too many in a depth map may lead to dimensioning errors. Providing feedback based on the number of null-data pixels helps a user understand and adapt to different dimensioning conditions, promotes accuracy, and facilitates handheld applications.

Abstract: A pointing device using proximity sensing is described. In an embodiment, a pointing device comprises a movement sensor and a proximity sensor. The movement sensor generates a first data sequence relating to sensed movement of the pointing device relative to a surface. The proximity sensor generates a second data sequence relating to sensed movement relative to the pointing device of one or more objects in proximity to the pointing device. In embodiments, data from the movement sensor of the pointing device is read and the movement of the pointing device relative to the surface is determined. Data from the proximity sensor is also read, and a sequence of sensor images of one or more objects in proximity to the pointing device are generated. The sensor images are analyzed to determine the movement of the one or more objects relative to the pointing device.

Abstract: A handheld dimensioning system that analyzes a depth map for null-data pixels to provide feedback is disclosed. Null-data pixels correspond to missing range data and having too many in a depth map may lead to dimensioning errors. Providing feedback based on the number of null-data pixels helps a user understand and adapt to different dimensioning conditions, promotes accuracy, and facilitates handheld applications.

Abstract: Embodiments described herein relate to a measuring device, comprising a base that defines a vertical axis, an assembly that can be pivoted about the vertical axis relative to the base, and a beam deflecting unit for varying the orientation of a measurement axis, wherein the beam deflecting unit can be rotated about a horizontal axis relative to the assembly. The measuring device further has a distance measurement functionality for measuring distance by means of the measurement radiation, an angle measurement functionality for determining an orientation of the measurement axis relative to the base, a control and processing unit for processing data and for controlling the measuring device, and a scanning functionality, wherein when the scanning functionality is executed, a scan is performed, and a point cloud comprising the scan points is produced. The assembly also has an imaging system. The measuring device may have a single-point measurement mode.

Abstract: An X-ray imaging apparatus comprises an X-ray source for irradiating X-rays to a subject; a sensor mounted on the source; and a controller for obtaining a volume of the subject based on an output value of the sensor, determining a degree of obesity of the subject based on the volume, and controlling an irradiation level of the X-rays based on the degree of obesity of the subject, wherein the output value of the sensor comprises, if the sensor comprises multiple image sensors, tilting angles of the multiple image sensors while the X-ray source is being shifted. An X-ray imaging apparatus and method for controlling the same where characteristics, e.g., a degree of obesity, of a subject may be automatically detected. Based on the detected characteristics of the subject, an intensity of X-rays may be automatically controlled, thereby improving the quality of the X-ray image.

Abstract: Some embodiments described herein include a laser tracker for continuously tracking a reflective target and for determining the distance with respect to the target. The laser tracker may include beam directing unit for emitting a measurement radiation and for receiving at least part of the measurement radiation reflected at the target. The laser tracker additionally comprises an interferometer for determining a change in distance with respect to the target. A control and evaluation unit is designed in such a way that an interferometer wavelength of the measurement radiation is determined by defined sample measurements being carried out with variation of the distance with respect to the target, wherein the sample measurements are effected for at least two different distances with respect to the target, the measurement radiation is constantly oriented towards the target and with the interferometer wavelength being kept stable.

Abstract: A handheld dimensioning system that analyzes a depth map for null-data pixels to provide feedback is disclosed. Null-data pixels correspond to missing range data and having too many in a depth map may lead to dimensioning errors. Providing feedback based on the number of null-data pixels helps a user understand and adapt to different dimensioning conditions, promotes accuracy, and facilitates handheld applications.

Abstract: Disclosed herein is a protective film detecting method including the steps of supplying a mist to a work surface of a workpiece in the condition where the work surface is coated with a protective film, applying light to the work surface of the workpiece, imaging the work surface of the workpiece after supplying the mist, and detecting an uncoated area where the protective film is not formed, by using a difference in light intensity between a coated area where the protective film is formed and the uncoated area where the protective film is not formed to cause the formation of asperities due to droplets formed from the mist supplied to the work surface of the workpiece and the occurrence of Mie scattering of the light applied to the asperities, the difference in light intensity being detected from an image obtained in the imaging step.